An engine of a vehicle may be automatically stopped and started to conserve fuel. The engine may be stopped via a controller in response to vehicle operating conditions without receiving a specific request to stop the engine from a human driver or occupant of the vehicle. The engine may also be stopped via a request that is generated by the human driver. Some human drivers prefer to operate the engine in a conventional mode whereby automatic engine stopping and starting is deactivated or inhibited so that the engine remains running (e.g., combusting fuel and rotating) during vehicle operating conditions where the engine would otherwise be automatically stopped. The vehicle's human driver may deactivate or inhibit automatic engine stopping and starting via initiating a driver automatic engine stop/start inhibit request via a human/machine interface. The driver automatic engine stop/start inhibit request may in cleared so that the engine resumes automatic stopping and starting after the vehicle's human driver manually initiates an engine stop. However, the human driver may become agitated if he or she stops the engine and then returns to the vehicle a short time later to find that automatic engine stopping and starting has been reactivated. While automatically stopping and starting the engine may improve vehicle fuel economy, it may also result in driver dissatisfaction during some conditions where the driver prefers to keep the engine running.
The inventors herein have recognized the above-mentioned issues and have developed an engine operating method, comprising: inhibiting the automatic stopping and starting of the engine via a controller in response to a request made via a human/machine interface; and cancelling the request and allowing automatic stopping and starting of the engine via the controller in response to a human driver initiated engine stop and an engine temperature being less than a threshold temperature.
By canceling a request to inhibit automatic engine stopping and starting in response to a human driver initiated engine stop and an engine temperature being less than a threshold temperature, it may be possible to automatically reactivate automatic engine stopping and starting in a way that facilitates improved vehicle fuel economy without being objectionable to the vehicle's driver. In particular, reactivating automatic engine stopping and starting in response to engine temperature being less than the threshold temperature allows automatic engine stopping and starting to be reactivated after a longer period during which the engine was not operated. A vehicle's driver may be disturbed less when engine operation defaults back to automatic engine stopping and starting after an engine stop period during which the engine cooled down because engine operating conditions have changed since the engine was last operated and the driver is likely to understand the usefulness and necessity of improving vehicle fuel economy via automatic engine stopping and starting.
The present description may provide several advantages. In particular, the approaches may improve vehicle drivability for some drivers. Further, the approaches allow automatic engine stopping and starting to be inhibited or deactivated by a human driver, but the approach also automatically reactivates automatic engine stopping and starting so that the vehicle may achieve greater fuel economy. Further still, the approach may reactivate automatic engine stopping and starting in a way that may be more desirable to some drivers.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.